This is the way it has been designed. Once the child products are created they are treated as their own product in their own right. I can understand how this may be frustrating in some cases but I think the engineers who designed this sytem wanted to keep it as flexible as possible based on some lessons we learned with our V1 API.

If you would like to offer some feedback I can pass it back to our product team to look at.

Just to offer a bit more explanation, with the child items becoming unique products, this allows them to have a unique image for each product. If you were to inherit the main image child products would have to display that same image.

As an example a Large blue t-shirt would have a different image to a Small green t-shirt.